A particle beam that is flux of high-energy charged particles accelerated by and extracted from a synchrotron has been utilized in, for example, cancer treatment. It may be preferable in some particle beam treatments to select a kind of particle beam depending on a treatment target. For that reason, it is desired that different kinds of particle beams can be extracted from one synchrotron accelerator system. Since synchrotrons are for accelerating injected charged particles, i.e., ions, a synchrotron injector system is needed that injects different kinds of ions into a synchrotron so as to allow the different kinds of ions to be extracted from the synchrotron.
Patent Document 1 discloses a technology enabling all kinds of ions to be accelerated to given energy levels by one synchrotron. However, regarding the injector system for injecting the ions into the synchrotron, it only states that the ion beams to be injected are accelerated to a certain energy level by a pre-accelerator.
Moreover, Patent Document 2 describes that respective ion sources are necessary for generating a proton beam and a carbon beam to utilize both beams; however, no detail description is made about the pre-accelerator for injecting both ion beams into the synchrotron.
Furthermore, Patent Document 3 discloses a configuration of an APF-IH drift-tube linear accelerator that is capable of accelerating a particle beam such as a large current proton beam.